摘要
用a介质（n型掺杂GaAs）和b介质（TiO2）组成一含缺陷层的光子晶体。数值计算表明：此光子晶体在3．0—4．5THz范围内出现了5个透射率为1的缺陷模，这些缺陷模有如下特征：当n型掺杂GaAs的掺杂浓度n由10^17／cm^3增加到10^19／cm^3时，缺陷模的中心、半峰全宽度和透射率均保持不变，但若n增至10^20／cm^3，则缺陷模的透射率开始下降。入射角增加，缺陷模的透射率保持不变，但其中心发生蓝移，移动率为变量，且半峰全宽度变窄。a、b两介质或缺陷层C的几何厚度分别增加时，缺陷模的透射率和半峰全宽度分别保持不变，中心位置红移。这些现象为此类光子晶体实现太赫兹频段的梳状滤波提供了理论指导。
A photonic crystal containing defect layer was composed of a medium （n-type doped GaAs） and b medium （TiO2）. Numerical calculations indicate that there are 5 defect mode of 1 transmittance within 3.0-4.5 THz for the photonic crystal. These defect mode have following characteristics： when the doping concentration n of GaAs increases within 10^17/cm^3 to 10^19/cm^3, the center, the full width at half maximum （FWHM） and the transmittance of the defect mode remain unchanged, However, if n increased to 10^20/cm^3, the transmittance of the defect mode began to decline. With increasing angle of incidence, the transmittance of the defect mode remain unchanged, but their center blue-shift, the mobile rate are variable, and FWHM narrows. The central position of the defect mode occurs red shift with increasing the thickness of the media layer a, b or the defect layer c respectively, while both the transmittance and FWHM remain constant. These phenomena provide theoretical guidance for this type of photonic crystal to realize the comb filtering in terahertz frequency range.
出处
《红外与激光工程》
EI
CSCD
北大核心
2014年第6期1869-1872,共4页
Infrared and Laser Engineering
基金
湖北省教育厅科学技术研究项目(Q20122307)
关键词
光子晶体
掺杂半导体
缺陷模
太赫兹滤波
photonic crystal
defect mode
doped semiconductor
terahertz filtering
